Installing and upgrading help

You need the Microsoft Drivers for PHP for SQL Server to access SQL Server from PHP

Microsoft's driver doesn't have a production release for PHP 7.4 yet but there is a preview release.

Also Moodle 3.8 doesn't support PHP 7.4 yet (more info). You may not encounter problems but you should be aware of this.

If you wanted to go ahead with this then the steps should be:

1. Download the zip file containing the driver (this is probably the NTS x64 version if you have IIS).
2. Extract php_sqlsrv.dll to the PHP extensions directory, normally the ext subdirectory in the PHP directory.
3. Add extension=sqlsrv to the php.ini file.
4. You may need to restart the IIS service to detect the change.

The Microsoft Drivers for PHP for SQL Server have dependencies (Visual Studio run-time and ODBC I think) so you may need to download these if not already present, see System Requirements on the production driver download page for details.

Here's a command line test to see if the driver is installed to be run from the PHP directory:

cd ...\location\of\php.exe
.\php -r "echo 'sqlsrv_connect() ' . (function_exists('sqlsrv_connect') ? 'present' : 'not present') . PHP_EOL;"

This should display "sqlsrv_connect() present" if the driver is loaded correctly (and "not present" if it's not).